1. Technical Field
Exemplary embodiments of the present invention relate to a method of fine patterning a thin film, and a method of manufacturing a display substrate. More specifically, exemplary embodiments of the present invention relate to a method of fine patterning a thin film, and a method of manufacturing a display substrate using the method.
2. Discussion of Related Art
Generally, a liquid crystal display (LCD) panel includes a display substrate having a plurality of switching elements for driving each area or pixel, an opposite substrate facing the display substrate, and a liquid crystal layer interposed between the display substrate and the opposite substrate.
The display substrate includes a gate pattern, a source pattern and a pixel electrode that are stacked thereon. The gate pattern includes a gate line and a gate electrode connected to the gate line. The source pattern includes a data line crossing the gate line, a source electrode connected to the data line and a drain electrode spaced apart from the source electrode. The pixel electrode makes contact with the drain electrode, so that the pixel electrode is electrically connected to a switching element, such as a transistor.
The gate pattern, the source pattern and the pixel electrode are typically formed through a photolithography process. For example, a photoresist pattern is formed on a thin film, and then the thin film is dry-etched and/or wet-etched by using the photoresist pattern as an etch-stop layer.
In order to form a fine pattern using the photolithography process, an exposure apparatus of high resolution should be employed for reducing the width of a pattern. Recently, the width of the pattern may be formed to at least about 2 μm by using high resolution exposure apparatus. The exposure apparatus of high resolution may be expensive, however, when replacing older exposure apparatus.
Alternatively, the width of a pattern may be reduced by increasing an amount of exposure light used in the photolithography process. As the exposure light amount is increased, however, there may be limits to reducing the width of the pattern. Moreover, the contact time of the exposure apparatus may be increased as the exposure light amount is increased, so that the process time for the photolithography process may be extended.